Stabilizers for chlorine-containing resins and process for producing the same

Abstract

A stabilizer for chlorine-containing resins, comprising calcium hydroxide coated with a calcium salt of an organic acid, and a process for producing the same wherein calcium hydroxide and an organic acid are reacted at a molar ratio of 1 mole of calcium hydroxide: not more than 2 moles of organic acid in the presence of a medium and a surface active agent, while heating and stirring, to convert the outer surface of the calcium hydroxide to a calcium salt of the organic acid.

What is claimed is: 
     
       1. A process for producing a thermal stabilizer for chlorine-containing resins which comprises calcium hydroxide coated with a calcium salt of an organic acid selected from the group consisting of saturated fatty acids having 10-22 carbon atoms and mixtures thereof, where calcium hydroxide and said organic acid are reacted at a molar ratio of 1 mole of calcium hydroxide: not more than 2 moles of said organic acid, in the presence of an aqueous medium and a surface active agent selected from the group consisting of polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, fatty acid salts, sulfuric acid esters of higher alcohols, sulfuric acid esters of aliphatic amines or amides, quaternary ammonium salts and mixtures thereof, while heating and stirring at about 90° to 100° C., to convert the outer surface of the calcium hydroxide into a calcium salt of said organic acid. 
     
     
       2. The process of claim 1, wherein said organic acid is selected from the group consisting of stearic acid and palmitic acid. 
     
     
       3. The process of claim 1, wherein said calcium salt comprises from about 2 to about 10 wt% of said organic acid, based on the weight of said calcium hydroxide.